Journal of Sensory, Comparative. ~ , , and Physiology A Behavioral Physiology 9 Springer-Verlag 1987 The echolocation and hunting behavior of the bat,

Summary. The echolocation and hunting behavior of Pipistrellus kuhli was studied in the field using multi-exposure photography synchronized with high-speed tape recordings. During the search phase, the bats used 8-12 ms signals with sweeps (sweep width 3-6 kHz) and pulse intervals near 100 ms or less often near 200 ms (Figs. I and 2). The bats seemed to have individual terminal fre-quencies that could lie between 35 and 40 kHz. The duty cycle of searching signals was about 8%. The flight speed of hunting bats was between 4.0 and 4.5 m/s. The bats reacted to insect prey at dis-tances of about 70 to 120 cm. Given the flight speed, the detection distance was estimated to about 110 to 160 cm. Following detection the bat went into the approach phase where the FM sweep steepened (to about 60 kHz bandwidth) and the repetition rate increased (to about 30 Hz). The ter-minal phase or 'buzz', which indicates prey cap-ture (or attempted capture), was composed of two sections. The first section contained signals similar to those in the approach phase except hat the pulse duration decreased and the repetition rate increased. The second section was characterized by a sharp drop in the terminal frequency (to about 20 kHz) and by very short pulses (0.3 ms) at rates of up to 200 Hz (Figs. 1 and 3). Near the beginning of the buzz the bat prepared for capturing the prey by extending the wings and forming a tail pouch (Fig. 4). A pause of about 100 ms in sound emis-sion after the buzz indicated a successful capture (Fig. 4). Pulse duration is discussed in relation to glint detection and detection distance. It is argued that the minimum detection distance can be esti-mated from the pulse duration as the distance where pulse-echo verlap is avoided. Abbreviations: CF constant frequency, FM frequency modu-late